Can I tweak L-R balance by differntial biasing?

Doing that will probably make the 2 channels sound different from each other. I have no idea if you would be able to hear the difference if that's the case. But its something to consider.

All- sorry about the misspelled subject.
Zd542- I thought of that but desperate times call for desperate measures ;-) Also I was thinking about only going from 0.20v nominal to 0.19v. So far the bias seems rock steady so I might go to a more sensitive scale on my VOM and try going up 0.05v on one and down 0.05v on the other. I realize that the differential is the same but...who knows. I readily admit my technical ignorance so i thought i'd throw this out there any see if anyone has ever tried it.

Hi Michael,

I'm not 100% certain, but I don't think that approach would accomplish what you want. I believe that gain, which is what you are trying to change, will vary very slowly as bias is adjusted. If you want to unequalize the gains by say 2 or 3 db or more, I suspect that you would have to change the bias setting by much more than the maximum recommended reduction of 10%, even if you were to raise the setting in the other channel by a reasonable amount. That would most likely result in the sonic quality of the amp, as well as its maximum power capability, being considerably degraded.

Best regards,
-- Al

If you have to resort to biasing two channels or two amplifiers differently in an effort to achieve balance, where is the advantage of not having a balance control? It would seem the balance control would be much less intrusive. The other option is a preamp with a left and right volume control.

I think the bias idea is a bad idea. I would try balancing the room by rearranging furniture, window treatment, room treatment or whatever.

Bias has no effect on gain until the tubes begin to approach cutoff.

Reducing the bias will likely increase distortion, assuming that the amplifier design is optimized.

So the simple answer is 'no, this will not work.'